Objective Based on surface enhanced Raman spectroscopy technology， a rapid detection method for thiamethoxam in leaf vegetables was established.Methods Using gold nanoparticles as the reinforced base and carbon nanocages with porous structure as the purifying agent， the interference of pigment and organic acid in vegetable was effectively removed based on its large specific surface area and strong adsorption capacity.Results The limit of detection was 1 mg/kg. In the range of 0.5-15 mg/kg of thiamethoxam， the linear relationship was good. The recoveries ranged from 90.7% to 121.7% with relative standard deviation of 2.3%-7.5%.Conclusion This method has high sensitivity， simple and rapid operation， and it is suitable for the rapid determination of thiamethoxam residues in vegetables by grass-roots supervision departments.